Modeling studies of current Modeling studies of current and future extreme climatic and future extreme climatic

events in Europe within the EU events in Europe within the EU project PRUDENCEproject PRUDENCE

Ole B. Christensen, David B. Stephenson, Jens H. Christensen, Martin Beniston, Chris Ferro, Christoph Frei,

Stéphane Goyette, Kirsten Halsnæs, Tom Holt, Kirsti Jylhä, Brigitte Koffi, Jean Palutikof, Regina Schöll, Tido Semmler,

Katja Woth

Highlights of PRUDENCE

Results on future extreme events

simulated by Regional Climate Models

PRUDENCE participantsPRUDENCE participants1. Danish Meteorological Institute, Copenhagen, DK2. CINECA, Bologna, IT3. Météo-France/CNRM, Toulouse, FRA4. Deutsches Zentrum für Luft- und Raumfahrt e.V., Weßling, GER5. Hadley Centre for Climate Prediction and Research, Met Office, Bracknell, UK6. Climate Research ETH (Eidsgenössische Technische Hochschule), Zürich, CH7. GKSS Research Center (Institute for Coastal Research), Geesthacht, GER8. Max-Planck-Institut für Meteorologie, Hamburg, GER9. Swedish Meteorological and Hydrological Institute, Rossby Centre, Norrköping, SWE10. Universidad Complutense, Madrid, SP11. Universidad Politecnica, Madrid, SP12. International Centre for Theoretical Physics, Trieste, IT13. Danish Institute of Agricultural Sciences, Foulum, DK14. Risø National Laboratory, System Analysis Dept., DK15. University of Fribourg, CH16. Finnish Environmental Institute, Helsinki, FIN17. University of Reading, UK18. University of Lund, SWE19. Centre International de Recherche sur l’Environnement et le Développement, SMASH, Paris, FRA20. Climate Research Unit, University of East Anglia, UK21. Finnish Meteorological Institute, Associated to FEI (No. 16), FINA. Norwegian Meteorological Institute, Blindern, NOB. Royal Dutch Meteorological Institute, De Bilt, NLC. UQAM, Montreal, CAND. CSIRO, Victoria, AUSE. Czech Republic, Israel, Greece, Belgium, Slovakia………………..F. Munich-Re, Electricité de France, Elforsk, Hamburg Institute of International Economics,

Uni-Münster, DG-Research, STARDEX, MICE

PRUDENCE objectivesPRUDENCE objectives A series of high resolution climate change scenarios for 2071-2100 for Europe

Characterize level of confidence and variability related to model formulations and climate natural/internal variability

Assess the uncertainty in European regional scenarios resulting from model formulation

Quantitatively assess the risks arising from changes in regional climate over Europe, and estimate changes in extremes like heat waves, flooding and wind storms, by providing a robust estimation of the likelihood and magnitude of the changes

Demonstrate the value of the wide-ranging scenarios by applying them to impacts models focusing on effects on adaptation and mitigation strategies

Assess socio-economic and policy related decisions for which such improved scenarios could be beneficial

Disseminate the results of PRUDENCE widely …

150km globalatmospheric

GCM

50km regional climate model (RCM) for any

region

Coupled GCM (300km atmosphere)

A modelling system for detailed regional scenarios – the PRUDENCE

method

SST/sea-ice change from coupled GCM

Improved circulation from 150km atmospheric GCM

PRUDENCE protocolPRUDENCE protocol

High resolution A-GCM using 1961-1990 observed SSTs Better control climate than low resolution CGCM

High resolution A-GCM using SST anomalies for 2070-2100 from transient CGCM experiment Greenhouse gas concentrations and aerosols according to

IPCC SRES scenarios (A2, B2)

HadAM3H, HadAM3P (PRECIS), Arpege, FVGCM, ECHAM5

Available daily fieldsAvailable daily fields T_2m (K) Precipitation (mm/day) Total cloudiness (Fraction) Evapotranspiration (mm/day) Snow water equivalent (mm) total runoff (mm/d) soil moisture (mm) Surface pressure (hPa) MSLP (hPa) T_2m_max (K) T_2m_min (K) 10-m wind speed (m/s) 10-m daily max wind speed (m/s) 2m specific humidity (kg/kg) net and downward SW and LW radiation (W/m2) positive

downward

Availability of dataAvailability of data

The PRUDENCE data are now public. Daily, monthly, and seasonal RCM data can be downloaded from http://prudence.dmi.dk/

Please let us know what you will be doing in order to avoid duplication of efforts

We are happy to answer questions

You must acknowledge the PRUDENCE project

PRUDENCE work on extremesPRUDENCE work on extremes

Better understanding of how European weather and climate extremes are likely to change:

Heat waves

Precipitation – heavy and low

Wind storms and storm surges

MethodologiesMethodologies  Maxima Percentiles Indices

Temperature 

  99th percentile of daily maximum temperature

Number of exceedances of 30°C; number, frequency, duration, and intensity of heat waves (6 consecutive exceedances of 90th temperature percentile)

Precipitation Maximum summer 1-day and winter 5-day totals

95th percentile of summer 1-day totals

Annual maximum dry- and wet-spell lengths

Wind storms

Annual maximum storm surge

90th and 99th percentiles of winter 10-metre wind speed; 10th percentile of winter sea-level pressure

Number of exceedances of 90th, 95th and 99th wind-speed percentiles; number of exceedances of Beaufort thresholds

TemperatureTemperature

Number of days/yr > 30Number of days/yr > 30°°CC

Northward shift of heat waves e.g. Paris: 9 days/yr 50 days/yr

1961-90 HIRHAM CTL

2071-2100 HIRHAM A2

Percentage change in 99Percentage change in 99thth percentile percentile

Changes in variance have a big impact on high extremes

Fraction of change left after correcting for the change in the location (median)

After correctingfor the change in the location and scale (median and IQR)

HIRHAM

Schär et al. (2003)

Schär et al. (2003)

Schär et al. (2003)

Relative changes in heat wave indicesRelative changes in heat wave indicesDuration

Frequency

Intensity

Number

Increased frequency, intensity and duration of heat waves

HIRHAM

PrecipitationPrecipitation

5-yr GEV return levels of daily 5-yr GEV return levels of daily precipitationprecipitation

REMO Control run German Weather Service Obs

RCM is capable of reproducing observed 5-year extremesin Baden-Württemberg, Germany

Changes in HIRHAM 5-year return levelsChanges in HIRHAM 5-year return levels5-day Winter precipitation Summer 1-day precipitation

Increases over Europe except for decreases in south in summer

HIRHAM

Christensen & Christensen, Nature (2003)

Sensitivity due to GCM and RCM resolutionSensitivity due to GCM and RCM resolution

ECHAM HC 50km HC 25km

Sensitivity of response to RCMSensitivity of response to RCM

More consistent +10% increase in winter Strong sensitivity to RCM formulation in summer

Winter precipitation Summer precipitation

Uncertainty due to driving GCMUncertainty due to driving GCM

ECHAM4-HIRHAM HadAM3H-HIRHAM

ECHAM4-RCAO HadAM3H-RCAO

Patterns of change determined by GCM, magnitudes affected by RCM

Relative change in 95th percentile of summer 1-day precipitation

Uncertainty due to emission scenarioUncertainty due to emission scenario

Winter 5-day maxima increase; related but smaller increases in means;similar differences between RCMs, GCMs, scenarios, natural variability.Summer 1-day maxima increase; related decrease in means; largestdifferences due to RCM. Smaller changes for B2 than for A2.

A2 scenario change in max dry spell lengthA2 scenario change in max dry spell length

10oW 5oW 0o 5oE 10oE 15oE 20oE 25oE 30oE 35oE 35oN

40oN

45oN

50oN

-20

-10

0

10

20

30

40

Increased risk of drought in S. Europe esp. Spain/Portugal(one month longer drought/year than present!)

daysHIRHAM+HADRM3+RCAO

A2 change in 100-yr max wet-spell lengthA2 change in 100-yr max wet-spell length

10oW 5oW 0o 5oE 10oE 15oE 20oE 25oE 30oE 35oE 35oN

40oN

45oN

50oN

-30

-20

-10

0

10

20

30

10oW 5oW 0o 5oE 10oE 15oE 20oE 25oE 30oE 35oE 35oN

40oN

45oN

50oN

-30

-20

-10

0

10

20

30

10oW 5oW 0o 5oE 10oE 15oE 20oE 25oE 30oE 35oE 35oN

40oN

45oN

50oN

-30

-20

-10

0

10

20

30

10oW 5oW 0o 5oE 10oE 15oE 20oE 25oE 30oE 35oE 35oN

40oN

45oN

50oN

-30

-20

-10

0

10

20

30

HadRM3P

HIRHAMRCAO-HadAM3H

RCAO-ECHAM

Widespread reductions Variation due to driving GCM and RCM greater than scenario

WindWind

% change in 90% change in 90thth percentile of 10-metre wind speed percentile of 10-metre wind speed

Increased wind speed intensity in core of Europe north of Alps

RCAO

Change in mean sea-level pressureChange in mean sea-level pressure

More cyclonic low pressure conditions in winter

CHRM

A2 changes in max winter surge heightsA2 changes in max winter surge heights

HIRHAM

Largest change of 0.3 metres on coasts near German bightChanges (meters) in max surge heights from HadAM3H / HIRHAM.

North Sea surge height changesNorth Sea surge height changesChanges in surge heights along the North Sea coast (red line). The grey area marks the 95% confidence of interannnual variability, and the four lines the estimates by four participating regional climate models, which all downscale the same global climate change scenario prepared with the Hadley Center model and the A2 scenario.

Watch out Holland, Germany and Denmark!

ConclusionsConclusions

• Heat waves – increased frequency, intensity, and duration of summer heat waves

• Increase in interannual variability of temperature

• Heavy precipitation – general increase except over S. Europe in summer. Central Europe will have less rainy days, but probably larger intensities

• Droughts – increased risk over S. Europe with much longer dry spells

• Wind storms – increased intensity and frequency of high wind speed events in winter

• Storm surges – increase in maximum storm surge level of up to 0.3 metres especially near the German Bight.

More details in forthcoming paper …

‘Future extreme events in European climate: An exploration of regional climate model

projections’

Beniston et al., 2005

Climatic Change (PRUDENCE special issue)